The surface structure of titanium dioxide thin film photocatalyst

The surface structure of TiO2 thin film photocatalyst was successfully controlled by the sol-gel method with a polymer doped dip-coating process. The thin films prepared were either transparent or translucent depending on the molecular weight of the polymer doped. The surface of the transparent thin films looked plain consisting of uniformly aggregated nanometer size TiO2 particles, while the translucent thin film was formed with cubic-like crystalline TiO2 at a micrometer level, The specific surface area of the transparent thin film was almost the same as that of the translucent one. All the thin film photocatalysts had an anatase structure with similar crystallinity. Both the transparent and translucent films showed catalytic activity for NOx elimination from air. The activity was almost equal to the commercial photocatalyst P25. (C) 1997 Elsevier Science B.V.